Submersible electrical motors are typically used to drive submersible well pumps that may be used in oil well production. These motors generate heat that is preferably removed during operation to prevent overheating of the motor.
One method of removing the heat generated by the motor is filling the motor housing with a dielectric liquid or lubricant. The lubricant removes heat from motor components and transfers it to a motor housing. The motor housing may in turn transfer the heat to the well fluid in which it is immersed. However, the prior art lubricant in the housing generally does not have good thermal conductivity and is not very effective at removing the heat generated by the motor while it operates. Also, air pockets tend to exist in the housing, which also contributes to poor thermal conductivity. A motor's performance and life is thus poorly affected due to poor heat removal.
Thus enhanced heat transfer can extend the life of the motor due to the lower operating temperature. Further, if the motor's internal temperature is kept at the same operating temperature, the motor can reliably and efficiently operate in higher outside temperatures.
The fabrication of motors that operate reliably and effectively is desired. Current methods of removing heat from motors are ineffective. A need exists for a technique to enhance heat transfer in motors.